This invention relates generally to the field of disc drive data storage devices. More specifically, the invention relates to a retaining ring for a spindle motor for spinning the discs on which data is recorded in such a device.
Disc drive data storage devices of the "Winchester" type are well-known in the industry. Such devices utilize rigid discs coated with a magnetizable medium for the storage of digital information in a plurality of circular concentric tracks. This information is written to and read from the discs using a data head mounted on an actuator mechanism which moves the head from track to track across the surface of the disc under control of electronic circuitry. The discs are mounted for rotation on a spindle motor which causes the discs to spin and the surface of the discs to pass under the heads.
Early five 1/4 inch Winchester disc drives included a brushless DC spindle motor which was mounted to a base of a drive housing. The actual motor components were outside of the housing and a shaft of the motor projected into the housing where it was coupled to a hub which was used to mount the discs.
As industry demands for smaller sizes of disc drives has lead to the introduction of half-height five and one-quarter inch drives, three and one-half inch, two and one-half inch, 1.8 inch and smaller drives, the size and configuration of the spindle drive motor has also changed. "Pancake" spindle motors have been used which employ an air gap in the motor which was positioned axially to the motor shaft. "In-hub" spindle motors used motor coils and magnets which were located inside the disc carrying hub.
Current and future generations of disc drives continue to shrink from 2.5 inch to 1.8 inch form factors and smaller. However, many of the assembly steps remain manual and require human interaction. For example, stator windings in the spindle motor are manually positioned and conductively attached to form an external connection. Additionally, with such small size drives the stiffness of the assembly becomes an issue because it can lead to undesired resonances which can limit performance of the disc drive.